23/06/2018: A previous version of this article erroneously referred to Ibrahim Kalin as the spokesperson for the AK Party and President Erdogan. Kalin is the spokesperson for the Turkish presidency. This has been corrected.

Millions of Turkish voters will head to the polls on June 24 to simultaneously elect a president and new members of parliament. It's the first time since the referendum last year when the people approved key constitutional amendments - giving more power to the presidency.

Incumbent President Recep Tayyip Erdogan and the ruling Justice and Development Party (AK Party) argue that a more powerful executive presidency helps Turkey tackle economic and security challenges.

But critics like Temel Karamollaoglu, presidential candidate and leader of the Saadet Party, warns that Erdogan is moving the country to a dictatorship and says the president is not doing enough to unite the Muslim world abroad.

Just because he [Erdogan] keeps winning, it doesn't make him an authoritarian person.

Ibrahim Kalin, Turkish presidential spokesperson

"The new presidential system is going to lead Turkey to a dictatorship," Karamollaoglu says. "There is no doubt, because the parliament has no influence on the president. They can't control, they can't produce any values which will be effective, so the president, in fact, will decide whatever he thinks proper without consulting the parliament."

And although the Turkish people voted for the constitutional changes last year, Karamollaoglu says, "the public can make mistakes as well. It will be too late when they see, realise what the dangers are and what they will face."

"We believe in separation of power ... The government should not have any influence on justice, on the courts. Today, the government directly controls and gives in fact orders to the courts. You can't have justice in a world like this," he says.

Asked about his chance to winning the presidency, he says, "there are some rumours that certain tricks are prepared, but we don't know what will happen. When you take part in elections, you go there to win."

President Erdogan has been ruling Turkey for more than 15 years, and his spokesperson is confident that he will win another term - with increased powers.

"Those who claim that the new system will be some kind of an authoritarian autocracy, one-man rule, etc, they should study political history and look at examples of other presidential systems," says Ibrahim Kalin, the spokesperson for the Turkish presidency.

"If you look at for example, how much power an American president has, it's not any different ... The presidential system cannot be called an authoritarian system. In fact, if you look at the model itself, the full separation of powers - judiciary, executive and legislative - that is fully separated in the presidential system."

The government should not have any influence on justice, on the courts. Today, the government directly controls and gives in fact orders to the courts. You can't have justice in a world like this.

Temel Karamollaoglu, leader of the Saadet Party

According to Kalin, "the judiciary used to be dominated by a kind of a more secularist type of judges and prosecuters in the past. Then what happend in the last five, six years was, the Gulenists infiltrated the judiciary ... they put their people in key positions of the judiciary - prosecuters and judges ... and they were controlling the judiciary. We have eliminated the Gulenists from the judiciary ... They are independent."

Some opinion polls suggest a tight race and some have suggested that Erdogan's AK Party might not achieve a parliamentary majority, but Kalin says there is no doubt about the election outcome.

"I think most of the criticism that you get from some western media outlets and commentators is based on a total misreading of the political realities in Turkey ... Erdogan has entered almost 14 or 15 general, local elections and referendums over the last 14, 15 years and he has won every single one of them," he says.

"The vote on Sunday is not going to be any different according to the polls and to what we see on the ground ... We see the crowds on the streets, and their aspirations and their expectations from the government and from the leadership - it's very clear that he is set to win this election as well."

"Just because he keeps winning, it doesn't make him an authoritarian person."

On this episode of Talk to Al Jazeera,Temel Karamollaoglu, the leader of the Saadet Party, and Ibrahim Kalin, the spokesperson for the Turkish presidency, discuss Turkey's upcoming election, Erdogan's foreign policies and challenges facing the country.